The equation representing Jane's savings is 3 ( 2 ) t = 1 , 536 . She will have enough money to purchase the bike after t = 9 months. Therefore, the correct answer is option D.
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Set up the equation representing Jane's savings: 3 × 2 t = 1536 .
Divide both sides by 3: 2 t = 512 .
Express 512 as a power of 2: 512 = 2 9 .
Solve for t : t = 9 . The correct answer is D. 3 ( 2 ) t = 1 , 536 ; t = 9 .
Explanation
Problem Analysis Jane starts with $3 and doubles her savings each month. We need to find the equation that models this situation and determine how many months it will take for her to save $1 , 536 .
Setting up the Equation The equation representing Jane's savings is given by: 3 × 2 t = 1536 where t is the number of months.
Isolating the Exponential Term To solve for t , we first divide both sides of the equation by 3: 3 3 × 2 t = 3 1536 2 t = 512
Expressing 512 as a Power of 2 Now, we need to express 512 as a power of 2. We know that: 512 = 2 9
Solving for t So, our equation becomes: 2 t = 2 9 Since the bases are equal, the exponents must be equal: t = 9
Final Answer Therefore, it will take Jane 9 months to save enough money to purchase the bike. The correct equation is 3 ( 2 ) t = 1 , 536 , and t = 9 .
Examples
Exponential growth, like Jane's savings, is a common phenomenon. Imagine a population of bacteria that doubles every hour. If you start with 3 bacteria, the equation 3 ( 2 ) t models the population after t hours. This type of calculation is crucial in fields like biology, finance (compound interest), and even computer science (algorithm complexity). Understanding exponential growth helps in predicting outcomes and making informed decisions.